XStream the problem of converting underscores

XStream bugs, such as the underscore "_" in the definition alias, will become "__" after being converted to XML
Like what:

XStream stream=new XStream (); Stream.alias ("person", person.class); String Message=stream.toxml (person);

If there is a field in the person class Per_name has _ converted to XML, it will appear __ <per__name></per__name>

How does this need to be solved?

XStream XStream = new XStream (new Xppdriver (New Xmlfriendlynamecoder ("_-", "_"));

Because _ is a keyword, the default will change to __
$ is also the keyword, the default is _-, which 2 parameters a change the display of $, a change _ the display

XStream the problem of converting underscores